Abstract

A drift chamber, which makes possible the identification of charged particles in the momentum range 5–100 GeV/c by taking 192 samples of the ionization which they produce in 1.6 cm of 80% argon–20% CO2, has been constructed and tested. It is 1×1×3 m in the sampling direction and is operated at a pressure slightly above atmospheric. It has been found to be very stable in operation and to give an average resolution for the average charge distribution of 8.13±0.18% (FWHM) in agreement with the predicted value of 8.4%.